The present invention concerns a device for electrically driving a shutter with articulated elements.
Such shutters are well known and consist of a series of rectangular panels, the largest dimension of which extends horizontally, these panels being connected to one another, by their horizontal edges, by means of articulations. The lateral edges of these panels are provided with running rollers or similar mechanisms which run in guide rails, by means of which the shutter is guided from its open position to its closed position and vice versa. These rails each have a first rectilinear part (in general, vertical in substance) mounted in a fixed manner along one side of the door opening, the upper part of this first rectilinear part being connected, by means of a curved part, to a second rectilinear part (and generally horizontal in substance) mounted in a fixed manner in the plane which the shutter is to occupy in its open position.
Such shutters are normally used as garage doors or warehouse doors, but also as road vehicle doors and in particular as rear doors of trucks or vans.
These shutters can optionally be activated manually, which can often be done without too much difficulty, at least when the shutters are not too large and, in particular, too tall.
This is because, as a general rule, such shutters are provided with a balancing spring device that pulls the shutter towards its open position and thus counterbalances, at least approximately or partially, the weight of the shutter that pulls it towards its closed position.
In many cases, it is however desirable that such a shutter is equipped with an electrical drive device. Many types of device have already been designed and proposed to that end.
U.S. Pat. No. 2,560,236 describes an electrical drive device for a door shutter, in which the mechanical transmission between the electric motor and the upper element of the shutter comprises a chain (of the Galle chain or roller chain type) guided in a rail.
U.S. Pat. No. 2,922,638 describes a device for electrically driving a garage door. This device comprises an electric motor and a drive shaft both carried by arms fixed in an articulated manner to the upper element of the shutter. A belt and pulley transmission is provided between the motor shaft and the drive shaft. The latter carries a pinion at each of its two ends. These two pinions mesh with racks mounted along the horizontal part of the shutter guide rails.
EP-0 291 171 describes a door shutter for trucks equipped with a drive device with an electric motor. This device comprises a system of winches and belts, at least one of these belts having one end fixed to an element at the bottom of the shutter and at least one other belt having one end fixed to an element at the top of the shutter.
The door shutter described in NL 8902808 has a number of points of similarity with that described in EP-0 291 171, but the belts (which are preferably notched belts) are fixed by one of their ends to an element at the bottom of the shutter and by their other end to an element at the top of the shutter.
EP-0 222 204 describes a shutter with articulated elements, equipped with one or more electric motors activating a pinion which meshes with a rack mounted parallel to the rails of the shutter. The motor or motors is (are) fixed against one of the elements of the shutter, on the side turned towards the inside of the room or space closed by this shutter. When the shutter is in the open position, the motor (or each motor) is therefore suspended under the shutter element to which it is fixed.
A proposal has been made to drive truck shutters by a hydraulic system that comprises one or two hydraulic jacks situated close to the ceiling of the load space of the truck and the end of the piston rod of which is connected, in an articulated manner, to the upper element of the shutter.
Such a hydraulic system involves the use of very long jacks, which furthermore limits its application possibilities to sufficiently long trucks. This is because, when the shutter is closed, the total length of the jack (cylinder+piston rod) is necessarily a little greater than twice the height of the shutter.
To remedy this drawback, the device described in NL 9000459 comprises a double acting pneumatic cylinder, with free-floating piston (without a piston rod). The movement of this free-floating piston is transmitted to a sliding sleeve disposed around the pneumatic cylinder, by virtue of the fact that this piston and this sleeve are both provided with magnetic elements. The sliding sleeve is connected to one element (lower or upper) of the shutter. It will be understood that the magnetic (and not mechanical) connection between the piston and the sleeve can be a source of problems and also limit the application of such a system to relatively small and light shutters.
Certain of the shutter electrical drive devices which have been proposed up to now have been considered fairly satisfactory and notably fairly reliable, as long as they were used for equipping garage doors, warehouse doors or other building shutters.
Generally speaking, these shutter electrical drive devices have not given satisfaction when they have been used for equipping doors of trucks or similar vehicles; on account of their sometimes faulty operation and too many failures, they are considered to be insufficiently reliable. This observation also applies to the electrical drive devices that are nevertheless presented as being especially designed to equip vehicle shutters.
The fact that one and the same shutter electrical drive device can give satisfaction when it is used for equipping a garage shutter and, on the other hand, suffers too many failures when used for equipping a truck shutter, is due to a number of causes. The main one of these causes of difficulties and breakdowns is due to the fact that, when the truck starts, runs and stops, the electrical drive device of the shutter and the mechanisms composing it are subject to incessant vibrations and jolts which have particularly harmful effects when the truck runs on bumpy roads.
With vehicle shutter electrical drive devices proposed up to now, it may also be noted that these vibrations and jolts can cause at least partial opening of the vehicle shutter during running. Keeping such a shutter in the closed position by means of a lock, latch or similar fastening device is considered to be an unacceptable solution, notably because of the waste of time this involves.
Generally speaking, the truck shutter electrical drive devices proposed up to now are also too bulky. For this reason, they reduce the load capacity of the trucks to an unacceptable extent.
There is, however, a real demand for shutter electrical drive devices operating in a truly satisfactory and reliable manner for equipping doors of trucks or similar vehicles therewith.
It will be understood that such a device must not only be reliable, so as to be able to be used for a long time without notable risk of failure, but it must also be compact, so as to reduce the load capacity of the truck as little as possible.
The aim of the present invention is to provide such a device.
The electrical drive device according to the invention has been designed and perfected for equipping shutters of trucks or similar vehicles therewith, but this device can obviously also advantageously be used for equipping garage shutters, warehouse shutters or other building shutters therewith.
One object of the present invention is a shutter with articulated elements, the movement of which between a closed position and an open position, and vice versa, is guided by two rails disposed along the path that is to be followed by guide rollers with which the lateral edges of the elements of the shutter are provided. These guide rails each have a first rectilinear part mounted in the plane that the shutter is to occupy, in substance, in its closed position, this first part being connected by means of a curved part to a second rectilinear part mounted in the plane that the shutter is to occupy, in substance, in its open position. The shutter according to the invention is equipped with an electrical drive device that has two drive tracks respectively mounted parallel along said second rectilinear part of the guide rails, and that also has:
1) a carriage disposed between the second rectilinear parts of the two guide rails, this carriage having:
a rigid frame carried and guided by said second rectilinear part of said guide rails for a translational movement parallel to this part of the two rails,
a drive shaft mounted able to rotate on said frame, a pinion or a notched wheel being fixed to each of the two ends of this shaft, these two pinions or notched wheels meshing respectively with the two drive tracks,
an electric motor, provided with a motor shaft, mounted on the frame and connected to an electrical supply,
a transmission between the motor and the drive shaft, the motor shaft and the drive shaft being situated higher than the level of said second rectilinear part of the guide rails,
2) connection mechanisms between the carriage and the shutter element closest thereto,
3) a control station capable of controlling the running and stopping of the motor and therefore of controlling the opening and closing of the shutter,
said carriage being capable of moving between extreme positions which correspond to the positions of complete closure and complete opening of the shutter, said connection mechanisms being provided with elastic elements which, when the carriage is in its extreme position which corresponds to the position of complete closure of the shutter, exert a pressure on the shutter element closest to the carriage.
It is important to note that the xe2x80x9cdrive tracksxe2x80x9d are elongated elements with which the pinions or notched wheels fixed to the ends of the drive shaft can mesh. The drive shafts can notably be racks (in which case rack pinions are fixed to the ends of the drive shaft) or notched belts (in which case notched wheels are fixed to the ends of the drive shaft). The drive tracks can optionally also be chains such as Galle chains or roller chains (in which case pinions or wheels for appropriate chains are fixed to the ends of the drive shaft).
As indicated above, the guide rails have xe2x80x9ca first rectilinear part mounted in the plane that the shutter is to occupy, in substance, in its closed positionxe2x80x9d. It is important to understand by this that this first rectilinear part of the rails is mounted in the plane that at least the major part of the shutter is to occupy when it is in its closed position. This is because, with the majority of shutters with articulated elements, the upper articulated element is in an oblique position with respect to the plane in which the rest of the shutter is disposed when said shutter is in its closed position, the guide rollers situated close to the upper edge of this upper articulated element being engaged in the curved part of the guide rails.
The same remark applies with regard to the plane in which the second part of the two guide rails is mounted, since the articulated element constituted by the bottom of the shutter when said shutter is in the closed position can possibly be in an oblique position with respect to the plane in which the rest of the shutter is disposed when said shutter is in its open position.
The guide rails preferably have a section that is U-shaped in substance, the opening of the U of each rail being directed towards the other rail. It is this type of rail that is usually used for guiding shutters with articulated elements. A U-shaped rail more specifically preferred will be described below in a description of one embodiment of the invention, referring to the accompanying drawings.
When use is made of these rails having a section which is U-shaped in substance, the frame is advantageously guided by running rollers with which the opposite sides of the frame are provided, these running rollers being engaged in the second rectilinear part of the two guide rails.
The frame is advantageously guided in the second rectilinear part of each of the two U-sectioned guide rails, by at least three running rollers. Two of these rollers are disposed so as to be able to run against a part of the rail that corresponds in substance to one of the branches of the U of its section, and the third of these rollers is disposed so as to be able to run against a part of the inside of the rail that corresponds in substance to the other branch of the U of its section.
The electrical supply of the electric motor mounted on the frame is achieved preferably by means of a system of sliding contacts comprising electrical contact rails fixed in place parallel to the drive tracks, and contact brushes carried by the carriage.
The electric motor is advantageously provided with a motor brake. It is also advantageous that this motor is provided with a disengaging mechanism capable of being activated manually.
According to one particular embodiment, the transmission between the motor and the drive shaft is a chain transmission, the motor shaft and the drive shaft each being equipped with a sprocket wheel.
According to another embodiment, the transmission between the motor and the drive shaft is a notched belt transmission, the motor shaft and the drive shaft each being equipped with a notched wheel. This kind of transmission notably offers the advantage of operation that has little noise.
Of course, other types of transmission can also be suitable, like for example a gear transmission.
It is advantageous that the connection mechanisms between the carriage and the shutter element closest thereto connect the carriage to at least two parts of this shutter element which are laterally spaced apart from one another, with respect to the direction of translational movement of this shutter element.
Even for fairly wide shutters, it is generally sufficient that these connection mechanisms connect the carriage to only two parts of the shutter element closest to the carriage. These two parts of this shutter element must preferably be situated symmetrically with respect to the middle of the width of the shutter and advantageously fairly close to the lateral edges thereof.
According to a preferred embodiment, the connection mechanisms between the carriage and the shutter element closest thereto comprise a gas piston buffer. When the shutter is brought into its position of closure, this gas piston buffer is compressed and thus holds the shutter firmly in its closed position. This gas piston buffer can optionally be replaced by another means fulfilling the same function, like for example a metal spring device.
The electrical drive device of the shutter must be provided with means that limit the possible movement of the carriage between extreme positions that correspond respectively to the complete opening and the complete closure of the shutter.
These means can notably consist of two end-of-travel switches that stop the motor when the carriage has reached one or other of these extreme positions.
These switches are fixed in place on the path of the carriage, adjustable activation mechanisms, capable of activating one or other of the two end-of-travel switches, being mounted on the carriage.
During opening of the shutter, one of the end-of-travel switches stops the motor (and therefore also the carriage and the shutter) when the shutter has reached its position of complete opening.
During closure of the shutter, another end-of-travel switch stops the motor when the carriage has gone past, by a small predetermined distance (a few centimeters, for example), its position which corresponds to complete closure of the shutter. When, during closure of the shutter, the latter has reached its position of complete closure, it is stopped in this position on account of its lower edge coming up against the door opening threshold, the floor of the truck or any stop whatsoever. At this time, the carriage still continues its movement over a small distance (a few centimeters) before being stopped as a result of activation of the end-of-travel switch. For this reason, the gas piston buffers, with which the connection mechanisms between the carriage and the shutter are provided, are compressed, so as to hold the shutter firmly in its closed position.
The means capable of limiting the translational movement of the carriage can also consist of a photoelectric cell-based electronic device or a proximity detector-based electronic device.
According to a preferred embodiment, the electrical drive device control station is a remote electrical control station. This type of control station is known per se and usually comprises a small housing containing the necessary electronic elements and provided with buttons which must be activated to control the opening or closing of the shutter. It is in any case clearly preferable that this control station is a secure station of the xe2x80x9cdead-manxe2x80x9d type, with which the movement of the shutter towards its position of opening or its position of closure can continue only as long as the corresponding control button is activated.
According to a first embodiment of the electrical drive device with which the shutter is equipped, said drive tracks consist of racks. In this case, a rack pinion is fixed to each of the two ends of the drive shaft, these two pinions meshing respectively with the two racks.
According to an advantageous embodiment, the second rectilinear part of each of the two guide rails extends, in the direction opposite to the curved part of this rail, beyond the end of the rack mounted along this rail. It must be understood that, by virtue of this particular arrangement, the rigid frame (and therefore the carriage) would remain guided and supported by the guide rails in the case where, moving in the direction which corresponds to the opening of the shutter, it goes past the position beyond which the pinions of the drive shaft have gone past the end of the racks and are therefore no longer meshed therewith. The advantages provided by this particular arrangement are explained in the remainder of this description.
According to a preferred embodiment, the two racks are respectively mounted above the second rectilinear part of the two guide rails. In this case, the teeth of the two racks are preferably situated at the opposite side to the guide rails above which they are mounted, that is to say, the racks are disposed with their toothed part situated upward.
It is generally advantageous that the two racks are respectively immovably attached to the guide rails above which they are mounted.
According to a second embodiment of the electrical drive device with which the shutter is equipped, said drive tracks consist of notched belts. In this case, a notched wheel is fixed to each of the two ends of the drive shaft, these two notched wheels meshing respectively with the two notched belts.
Each of the two notched belts is fixed parallel along the second rectilinear part of a guide rail. Each of the two ends of each notched belt is fixed to a fixing support. At least one of these supports is provided with means for exerting and maintaining an appropriate tension on the notched belt.
The two notched belts are preferably respectively mounted above the second rectilinear part of the two guide rails.
According to an advantageous embodiment, the notched side of the notched belts is turned downward.
Two free deflecting wheels keep each notched belt, constituting a drive track, meshed with the corresponding notched wheel. These two deflecting wheels preferably keep each notched belt meshed with at least one third of the circumference of the corresponding notched wheel.
Another object of the invention is a device for electrically driving a shutter with articulated elements, the movement of which between a closed position and an open position, and vice versa, is guided by two rails disposed along the path that is to be followed by guide rollers with which the lateral edges of the shutter elements are provided. These guide rails each have a first rectilinear part mounted in the plane that the shutter is to occupy, in substance, in its closed position, this first part being connected by means of a curved part to a second rectilinear part mounted in the plane that the shutter is to occupy, in substance, in its open position. This device has two drive tracks capable of being respectively mounted parallel along said second rectilinear part of the two guide rails, and also has:
1) a carriage capable of being disposed between the second rectilinear parts of the two guide rails, this carriage having:
a rigid frame capable of being carried and guided by said second rectilinear part of said guide rails for a translational movement parallel to this part of the two rails,
a drive shaft mounted able to rotate on said frame, a pinion or a notched wheel being fixed to each of the two ends of this shaft, these two pinions or notched wheels meshing respectively with the two drive tracks,
an electric motor, provided with a motor shaft, mounted on the frame and connected to an electrical supply,
a transmission between the motor shaft and the drive shaft,
2) connection mechanisms, provided with elastic elements, capable of connecting the carriage to the shutter element closest thereto,
3) a control station capable of controlling the running and stopping of the motor and therefore of controlling the opening and closing of the shutter.
The disposition of the various elements constituting the device is such that, when said frame is carried and guided by said second rectilinear part of said guide rails, the motor shaft and the drive shaft are situated higher than this second part of the guide rails, and that said two pinions or notched wheels mesh respectively with the two drive tracks.
Another object of the invention is a road transport vehicle that has a shutter according to the invention. Usually, this shutter gives access to a space for loading goods.
Provision is made for an opening to be made in the bodywork of the vehicle according to the invention (generally in the roof of the body of the truck or van) close to the place where the disengaging mechanism for the motor of the electrical drive device for the shutter is situated, when this shutter is in the position of closure. This opening can be closed by a closure device such as, for example, a small flap mounted on hinges. Said opening makes it possible to have access, from outside the vehicle, to this disengaging mechanism and to activate it manually.
If an electrical fault (for example a fault in the vehicle battery) occurs while the shutter is closed, this particular arrangement makes it possible to manually activate said disengaging device and then manually open the shutter.
It is clearly advantageous that the closure of said closure device is made secure by a lock or a similar means.